A cup or cover stacker is known, particularly for a multirack cup filling apparatus for comestible items such as dairy products, in which a more or less continuous cup or cover column, i.e. column of lids or cups adapted to form a packaging container together, is divided into cup or cover partial stacks which are deposited on a horizontal conveyor positioned with clearance beneath a separating device by axially parallel spindle heads of the separating device engaging the cover or cup edges by circumferential scew threads.
In the known cup or cover stacker a theoretically unending cup or cover column is processed.
The cup or cover column is easily manipulatable because of its flexibility and is conveyed over spatially curved guides formed, e.g. by rods.
The separating device having four spindle heads provided on its delivery side has as its purpose to divide the cup or cover column into magazine-suitable partial stacks in which the cups or covers can be nested relatively firmly in one another.
Magazine-suitable means that the rows of partial stacks must be provided with the same number of partial stacks as the number of cup feed paths in the cup filling machine. In a four path cup filling apparatus, therefore, four partial stacks must be formed corresponding to the four cup or cover magazines (see our copending application Ser. No. 07/058,164, filed concurrently herewith (based upon German Patent document No. 3 619 519).
As soon as a certain partial stack height has been reached the separating device is stopped so that the spindle head prevents further unintended cup or cover dropping. While the separating device is idle the horizontal conveyor for transport of the partial stack is stepped.
In the known cup or cover stacker the separating device has the purpose of providing magazine-suitable partial stacks in which the covers or cups can sit on each other comparatively loosely for complication-free further processing which is not the case in the case with the normal cup or cover columns processed by the stacker.
Disadvantageously in the known cup or cover stacker after leaving the separating device a cup or cover travels to the horizontal conveyor by free fall. The partial stack formed by free fall can have inexactly or imprecisely positioned covers or cups, since the cup--particularly the cover--can be axially slid or tilted which can lead to trouble on further processing in subsequent removal from the magazine.
Mention may be made of U.S. Pat. No. 2,556,740 which discloses a system preventing free fall of cups but which does not fully solve the problems outlined above.